Collagen crosslinking for ectasia following PRK performed in excimer laser-assisted keratoplasty for keratoconus

PURPOSE. To report the results of corneal collagen crosslinking (CXL) in a patient with corneal ectasia developed after excimer laser-assisted lamellar keratoplasty for keratoconus and a secondary photorefractive keratectomy (PRK) for residual refractive error. METHODS. A 33-year-old woman, who had originally been treated for keratoconus in the right eye by excimer laser-assisted lamellar keratoplasty, subsequently had her residual ametropia treated by topographically guided, transepithelial excimer laser PRK. Five years after PRK, the patient developed corneal ectasia showing concomitant visual changes of best spectacle-corrected visual acuity (BSCVA) reduced to 20/33 with a refraction of -6.00 +6.00 x 30. The minimum corneal thickness at the ectasia apex was 406 pm. A treatment of riboflavin-UVA-induced corneal CXL was performed on the right eye. RESULTS. Two years after the CXL treatment, the right eye improved to 20/20 BSCVA with a refraction of plano +1.00 x 50 while exhibiting a clear lamellar graft. CONCLUSIONS. Corneal CXL provided safe and effective management of ectasia developed after excimer laser-assisted lamellar keratoplasty and PRK.